Modelling the Circulation and Sediment Distribution in the Athabasca Delta Area

Authors
R.A. Harrington
Resource Date:
1982
Page Length
125

This project undertook an assessment of the potential for using satellite imagery to determine water quality parameters in the southwest end of Lake Athabasca and to provide a mathematical model capable of simulating the circulation patterns in this area of the lake. A substantial amount of field data was collected for calibration purposes and served to ellucidate some of the hydraulic characteristics of the study area. The results indicated that water from the Athabasca River and its distributary channels could reach the north shore of the lake under conditions of moderately large inflow. It had been previously assumed that penetration of river water so far into the lake was unlikely. In addition, river water was found to extend up to at least 20 km northeast of the distributary channels. Water from the Embarras River and Fletcher Channel generally leaves the lake via the Chenal des Quatres Fourches while water from Big Point Channel generally discharges through the Riviere des Rochers. Correlation of LANDSAT imagery with contemporaneous water quality data yielded a high correlation between suspended sediment concentrations and band 6 digital response values. No other water quality parameters were correlated with the raw LANDSAT data. Principal component analysis of the satellite data indicated a high correlation between suspended sediment and the first principal component, which emphasized the infrared bands. In addition, conductivity was well correlated with the third principal component, which emphasized the difference between the visible bands. This result could prove beneficial in analysing satellite imagery since conductivity is a useful parameter for differentiating between lake and river water. A finite element model was developed which solves the vertically integrated momentum and continuity equations. Based on an implicit time stepping algorithm, the model was used to generate circulation patterns for an idealized representation of the study area.